Photographic element comprising polycarbonate having tertiary amine acid addition salt

ABSTRACT

Novel polycarbonate latex compositions comprising 0.1 to 30 mole percent of recurring units containing a carboxyl or a tertiary amine acid addition salt component are disclosed. The latex compositions are made by: (a) preparing a polycarbonate comprising from about 0.1 to 30 mole percent of recurring units having a carboxyl or a tertiary amine acid additon component; (b) dissolving the polycarbonate in a water miscible solvent having a boiling point below about 100 DEG C.; (c) blending the solution of (b) with water; and (d) removing the water-miscible solvent.

This is a division of application Ser. No. 091,249, filed Aug. 31, 1987.

FIELD OF THE INVENTION

This invention relates to novel polycarbonates, novel polycarbonatelatex compositions, novel methods of making such compositions and theuse of such compositions in elements.

BACKGROUND OF THE INVENTION

Polycarbonates are known as being tough and having good film-formingproperties which result in tough, strong polymer layers. Somepolycarbonates having recurring carboxyl components are used inapplications requiring hardness, elasticity and flexibility. Otherpolycarbonates having recurring alkylidene diphenylene components areused as binders in electrophotographic layers or as supports in silverhalide containing photographic elements.

However, polycarbonates are hydrophobic and layers of polycarbonates aregenerally coated from organic solvents. Coating from organic solventsresults in layers which are impermeable to water. Such layers areunsuited for use in hydrophilic photographic layers.

Emulsification of polycarbonates using surfactants and water-immiscibleorganic solvents or direct mechanical shearing of water-polycarbonatemixtures at high temperatures require excessive amounts of surfactants,or risk degradation and decomposition of the polycarbonate dispersions.The problem is that the particle size of the polycarbonates in suchemulsions is so large as to be unsuitable for use in the hydrophiliclayers such as are used in photographic elements.

SUMMARY OF THE INVENTION

The present invention provides novel latex compositions comprising anaqueous continuous phase having dispersed therein polycarbonateparticles characterized in that

(a) the polycarbonate comprises from about 0.1 to 30 mole percent ofrecurring units having a carboxyl or a tertiary amine acid addition saltcomponent, and

(b) the polycarbonate particles are less than about 0.3 μm in diameter.

The size of the polyester particles make the latex compositions suitablefor use in hydrophilic layers. Thus, the novel latex compositions of thepresent invention provide tough hydrophilic film forming polycarbonatelayers which are compatible with the hydrophilic emulsion layers used inelements such as photographic elements. The latex compositions arerelatively positive (anionic) or negative (cationic), depending uponwhether a carboxyl or a tertiary amine acid addition component ispresent in the polymer. Thus, the composition is useful in photographicelements which require compatibility with either negative or positiveaddenda.

The latex compositions are prepared by a novel method comprising thesteps of:

(a) preparing a polycarbonate comprising from about 0.1 to 30 molepercent of recurring units having a carboxyl or a tertiary amine acidaddition salt component;

(b) dissolving the polycarbonate in a water-miscible solvent having aboiling point below about 100° C.;

(c) blending the solution of (b) with water; and

(d) removing the water-miscible solvent.

No surfactants need be used in forming the latex composition. However,for some coating processes, surfactants are useful. In the latter casesno more than 3% by weight of surfactant, based on the total weight ofthe polycarbonate, should be mixed with the latex.

The polycarbonates having recurring tertiary amine components which areuseful in the latex compositions and in the method of making suchcompositions are novel.

In a preferred embodiment, the polycarbonates included in the latexcomposition have the structure ##STR1## wherein X is 0.1 to 30 molepercent;

R¹ represents a divalent organic group having a carboxyl or a tertiaryamine component, and

R² represents the divalent residue of any nonionic condensed diol.

DETAILED DESCRIPTION OF THE INVENTION

The polycarbonate polymers, including the novel polycarbonate polymershaving the recurring tertiary amine acid addition salt component used inthe preparation of the latex compositions of the invention are preparedby direct phosgenation or other well known procedures such astransesterification and polycondensation. Phosgenation was used for thepreparation of polycarbonates described in this invention. Phosgenationis carried out simply by contacting a solution of the starting materialswith gaseous phosgene.

Useful diols for making the polycarbonates include alkylene glycols,including dialkylene glycols, cyclic diols and trialkylene glycols andother diols well known in the art.

Useful cyclic diols for forming the R² residue include bisphenol A;4,4'-biphenol; 1,4-cyclohexanediol; 1,4-cyclohexanedimethanol;hydroquinone; 1,4-cyclohexanediethanol; 4,4'-oxybisphenol;2,7-naphthalenediol; 1,4-bis(2-hydroxyethoxy)cyclohexane;2,3-norbornanedimethanol; 1,4-benzenedimethanol and1,4-benzenediethanol.

Useful alkylene glycols for the R² residue include ethylene glycol;diethylene glycol; triethylene glycol; 1,2-propanediol; 1,3-propanediol;1,4-butanediol; 2,3-butanediol; 1,5-pentanediol; 1,6-hexanediol;1,7-heptanediol; 1,8-octanediol; 1,9-nonanediol; 1,10-decanediol;1,12-dodecanediol; 2,2,4-trimethyl-1,16-hexanediol;4-oxa-2,6-heptanediol and neopentyl glycol.

Useful starting materials for forming R¹ having a carboxyl componentinclude dihydroxy-substituted carboxylic acids, including aliphatic,alicyclic, and aromatic carboxylic acids including ammonium and alkalimetal salts thereof such as 2,2-bis(hydroxymethyl)propionic acid,1,2-dihydroxypropionic acid, α-resorcyclic acid, β-resorcylic acid(2,4-dihydroxybenzoic acid), γ-resorcyclic acid (2,6-dihydroxybenzoicacid), gentisic acid (2,5-dihydroxybenzoic acid), gentisinic acid,mesoxalic acid, 2,4-dihydroxycinnamic acid, dihydroxytartaric acid, andtheir salts.

Useful starting materials for forming R² having a tertiary aminecomponent include N-methyldiethanolamine, N-phenyldiethanolamine,3,5-bis(hydroxymethyl)-N,N-dimethylaniline, 2,4-dihydroxypyridine;2,6-dihydroxypyridine, 3-dimethylamino-1,2-propanediol and[bis(2-hydroxyethyl)amino]-1,2-propanediol.

In making polycarbonate latex compositions according to this invention,from 0.1 to 20%, preferably at least 2%, by weight of polycarbonate isdissolved in a water-miscible organic solvent. In some applications from10 to 20% by weight of polycarbonate is dissolved. The objective is tomake a composition having a total solids content of from 2 to 50%,preferably 5 to 35%. Useful water-miscible organic solvents in which thepolycarbonates are soluble include dimethylformamide, dimethylsulfoxide, tetrahydrofuran, acetone, dioxane, formic acid, phenol, andmixtures of such solvents.

Water is blended rapidly with the polycarbonate solution to insurehomogeneous nucleation. The organic solvent is then removed from theblend by evaporation or other conventional means, such as dialysis ordiafiltration, to form the loaded latex composition.

The polycarbonate latex compositions of this invention can be loadedwith one or more hydrophobic compounds. That is, one or more hydrophobiccompounds can be distributed, dissolved or otherwise associated with thepolycarbonate particles of the latex composition.

The process of loading (distributing, dissolving or associating) ahydrophobic compound within the loadable polymer particles isaccomplished in the following manner, described in U.S. Pat. No.4,214,047 which is expressly incorporated herein.

The hydrophobic compound (or hydrophobe) to be loaded is dissolved in awater-miscible organic solvent, and an aqueous latex consistingessentially of water as a continuous phase and loadable polymerparticles as a dispersed phase is then blended into the water-miscibleorganic solvent containing the hydrophobe. Blending is undertaken sothat the hydrophobe remains in solution and the loadable polymerparticles remain dispersed. That is, separation of the hydrophobe orcoagulation of the polymer particles is avoided.

By avoiding separation or coagulation of the hydrophobe or the polymerparticles, a two-phase mixture is established in which the continuousphase, the mixture of water-miscible organic solvent and water,constitutes one phase and the polymer particles constitute a secondphase. Initially, the hydrophobe is within the water-miscible organicsolvent. In the two phase mixture resulting from blending, thehydrophobe is brought into intimate association with both the continuousand the dispersed phases. The hydrophobe is then free to distributeitself between these phases based on its relative solubilities therein.Dilution of the water-miscible organic solvent with water by blendinghas the effect of reducing the affinity of the hydrophobe for thecontinuous phase. Thus, the introduction of water has the effect ofdriving or shifting the equilibrium distribution of the hydrophobe awayfrom the continuous phase and toward the dispersed phase. The presenceof water (or an increased amount of water, if some water was initiallypresent in the water-miscible organic solvent) causes the hydrophobe toredistribute itself between the continuous and dispersed phases. In thisway a portion of the hydrophobe becomes dispersed or dissolved in thepolymer particles, so that the polymer particles are loaded withhydrophobe. This loading procedure requires that the hydrophobe remaindissolved until associated with the polymer particle.

For a compound to be considered a hydrophobe, the compound must beessentially insoluble in distilled water at 25° C. Preferably thedissolved concentration of hydrophobe in water under these conditionsshould be less than 0.5 percent by weight, based on the weight of thewater. Any such hydrophobe is employed in the practice of this processwhich can be dissolved in a liquid consisting of one or a mixture ofwater-miscible organic solvents. Preferably the hydrophobe must besoluble in a concentration of at least 5 percent by weight, based on thetotal weight of the water-miscible organic solvent and dissolvedhydrophobe. In practice minor amounts of essentially diluent materials,such as minor amounts of water commonly entrained in water-misciblesolvents, are associated with the blended hydrophobe and water-miscibleorganic solvent; however, the hydrophobe and water-miscible organicsolvent or solvents are chosen so that additional materials, such as pHor other modifiers--e.g. acid or alkali--are not required to dissolvethe hydrophobe.

Specifically preferred hydrophobes, including photographic addenda, arethose used to perform coupling, silver halide development, oxidizeddeveloper scavenging, spectral sensitizing or desensitizing, diffusiontransfer dye image-forming and visible or ultraviolet light absorbingfunctions when incorporated in a silver halide photographic element.Other hydrophobes include those used in silver halide photographicelements as brighteners, antioxidants, silver halide solvents,bleachable dyes in silver-dye-bleach imaging processes and the like. Allthose hydrophobic photographic addenda which have been conventionallyintroduced into hydrophilic colloid layers of photographic elements incoupler-solvent and similar high boiling organic solvent droplets areideally suited for use in the practice of this invention.

In terms of end photographic uses all of the hydrophobic photographicaddenda useful as hydrophobes in the practice of this process can beintroduced in their conventional concentrations and locations withinphotographic materials and elements. Such photographic materials andelements are well known to chemists skilled in the photographic arts andneed not be discussed in detail herein. Photographic materials in thepreparation of which the process of the present invention is especiallyuseful include, for example, image transfer materials, physicaldevelopment materials, radiographic materials, dry development systems,color-forming materials, and the like, such as are described in ProductLicensing Index, Vol. 92, December, 1971, pages 107-110, and in BritishPat. No. 923,045.

The latex compositions including the loaded latex composition, can becoated as a layer with or without a hydrophilic colloid onto a usefulsubstrate, such as a conventional photographic support, usingconventional techniques. The compositions are coated using coatinghoppers and other apparatus conventionally employed in the photographicarts for forming single or multiple coatings on photographic supports.Useful coating techniques and supports are described in the ProductLicensing Index, Vol. 92, pages 107-110, December, 1971, and thepublications referred to therein.

Although these preferred embodiments are useful in the photographicindustry, the present invention is not limited to photographic materialsand processes, but is useful wherever it is deemed desirable to obtain adistribution of a hydrophobe through a polymeric material. Although thedistribution of hydrophobe through polymeric material is generally usedultimately in a layer on a support, other end uses are contemplated. Forexample, useful hydrophobes can include hydrophobic insecticides,herbicides, miticides, hormones, vitamins, enzymes and the like (whichmeet the requirements set out above). It will be appreciated that theend use of such loaded polyester latexes do not necessarily involve asupport.

The following examples are presented to further illustrate the presentinvention.

EXAMPLES 1-4

Polycarbonates prepared according to Examples 1-4 are shown below in theTable.

EXAMPLE 1 Preparation ofPoly(4,4'-isopropylidenebisphenylene-co-methyliminodiethylene carbonate)hydrochloride salt (Compound 1, Table I)

Phosgene was bubbled through a homogeneous solution comprising 98 g ofbisphenol A (0.43 mole), 12 g of N-methyldiethanolamine (0.1 mole), 700ml of methylene chloride and 80 ml of pyridine for a period of 6 hoursat 25°-30° C. The solution was then bubbled with nitrogen overnight,diluted to 2 liters with methylene chloride, filtered to remove thesalt, and then precipitated in methanol. After washing with methanol anddrying in a vacuum oven at 35° C., some 109 g of fluffy white polymerwere obtained. Tg=122° C.; reduced viscosity=0.39 (measured in THF at0.25%).

EXAMPLE 2 Preparation ofPoly(4,4'-isopropylidenebisphenylene-co-methyliminodiethylene-co-tetramethylenecarbonate) hydrochloride salt (Compound 2, Table I)

In a 2 liter flask were placed 45.7 g of bisphenol A (0.2 mole), 45 g of1,4-butanediol (0.5 mole), 12 g of CH₃ N(CH₂ CH₂ OH)₂ (0.1 mole), 142 gof pyridine (1.8 mole), and 700 ml of CH₂ CL₂. Phosgenation was carriedout as described in Example 1. After removing the salt, and recoveringthe polymer from methanol, 85 g of soft semi-solid polymer wereobtained.

EXAMPLE 3 Preparation ofPoly(2-carboxy-2-methyl-1,3-propylene-co-4,4'-isopropylidenebisphenylenecarbonate) (Compound 3, Table I)

Bisphenol A (91.32 g, 0.4 mole) and 2,2-bis(hydroxymethyl)propionic acid(13.4 g, 0.1 mole) were dried over 50 ml of toluene under vacuum at 80°C. for 10 minutes. The contents were then placed in a 2 liter flask,together with 95 g of pyridine (1.2 mole) and 700 ml of methylenechloride. Phosgene was bubbled through the solution at 25°-30° C. for atotal period of about 7 hours. After bubbling with nitrogen overnight,the salt was filtered off and most of the solvent was removed on arotary evaporator. The polymer was recovered as a white powder afterrepeatedly washing with methanol and drying at 45° C. in a vacuum oven.

EXAMPLE 4 Preparation ofPoly(2-carboxy-1,4-phenylene-co-4,4'-isopropylidenebisphenylenecarbonate (Compound 4, Table I)

In a 2 liter flask were placed 100 g of bisphenol A (0.45 mole), 10 g ofdihydroxybenzoic acid (0.065 mole), 95 g of pyridine (1.2 mole), and 700ml of CH₂ Cl₂. Phosgenation was carried out as in Example 3, and thepolymer was recovered in methanol as a white solid powder. The yield was81 g.

Other representative polycarbonates prepared according to the method ofthe invention are also presented in the Table.

                                      TABLE                                       __________________________________________________________________________     ##STR2##                                                                     Poly(4,4'-isopropylidenebiphenylene-co-methyliminodiethylene                  carbonate).hydrogen                                                           chloride                                                                       ##STR3##                                                                     Poly(4,4'-isopropylidenebiphenylene-co-methyliminodiethylene-co-tetramethy    lene                                                                          carbonate) hydrocloride salt                                                   ##STR4##                                                                     Poly(2-carboxy-2-methyl-1,3-propylene-co-4,4'isopropylidenebisphenylene       carbonate                                                                      ##STR5##                                                                     Poly(2-carboxy-1,4-phenylene-co-4,4'-isopropylidenebisphenylene               carbonate)                                                                     ##STR6##                                                                     Cationic                                                                      Poly(4,4'-isopropylidenebisphenylene-co-methyliminodiethylene-co-pentameth    ylene                                                                         carbonate).hydrogen chloride                                                   ##STR7##                                                                     Anionic                                                                       Poly(2-carboxy-1,4-phenylene-co-4,4'-isopropylidenebisphenylene               carbonate)                                                                     ##STR8##                                                                     Cationic                                                                      Poly(ethyliminodiethylene-co-4,4'-isopropylidenebisphenylene                  cabonate).hydrogen                                                            chloride                                                                       ##STR9##                                                                     Cationic                                                                      Poly(n-butyliminodiethylene-co-4,4'-isopropylidenebisphenylene                carbonate).hydrogen                                                           chloride                                                                       ##STR10##                                                                    Cationic                                                                      Poly(ethyliminodiethylene-co-4,4'-isopropylidenebisphenylene-co-pentamethy    lene                                                                          carbonate).hydrogen chloride                                                  10.                                                                            ##STR11##                                                                    Cationic                                                                      Poly(n-butyliminodiethylene-co-4,4'-isopropylidenebisphenylene-co-pentamet    hylene                                                                        carbonate).hydrogen chloride                                                   ##STR12##                                                                    Cationic                                                                      Poly(ethyliminodiethylene-co-4,4'-isopropylidenebisphenylene-co-tetramethy    lene                                                                          carbonate).hydrogen chloride                                                   ##STR13##                                                                    Cationic                                                                      Poly(n-butyliminodiethylene-co-4,4'-isopropylidenebisphenylene-co-tetramet    hylene                                                                        carbonate).hydrogen chloride                                                   ##STR14##                                                                    Anionic                                                                       Poly(2-carboxy-2-methyl-1,3-propylene-co-4,4'-isopropylidenebisphenylene-c    o-pentamethylene                                                              carbonate).                                                                    ##STR15##                                                                    Anionic                                                                       Poly(2-carboxy-2-methyl-1,3-propylene-co-4,4'-isopropylidenebisphenylene-c    o-tetramethylene                                                              carbonate)                                                                     ##STR16##                                                                     Anionic                                                                      Poly(4,4'-isopropylidenebisphenylene-co-pentamethylene-co-2-carboxy-1,4-ph    enylene                                                                       carbonate)                                                                     ##STR17##                                                                    Poly(4,4'-isopropylidenebisphenylene-co-2-carboxy-1,4-phenylene-co-tetrame    thylene carbonate)                                                            __________________________________________________________________________

EXAMPLE 5 Preparation of a Cationic Polycarbonate Latex

A sample of 30 g of the polymer obtained from Example 1 were dissolvedin 300 ml of tetrahydrofuran (THF) at room temperature. With gentlestirring, 200 ml of water were added to the above solution to obtain athin blue dispersion. The solvent (THF) and part of the water were thenremoved on a rotary evaporator at 50° C. under aspirator vacuum toobtain a polycarbonate latex of 21.5% total solids. Electron micrographsof the latex sample showed particles to be strikingly uniform withdiameters ranging from 0.02 μm to 0.025 μm. The latex was compatablewith quatanary ammonium salts such as hexadecyltrimethyl ammoniumbromide. The latex gave a clear coating with gelatin that is commonlyused in making photographic film and papers. This means that thepolymers will be compatible in photographic systems.

In a separate experiment, 11 g of polycarbonate from Example 2 weredissolved in 100 ml of acetone at room temperature, and the solution waspoured into 100 ml of distilled water with good stirring. Acetone andpart of the water were removed under vacuum at 50° C. to give a latex of13.6% total solids.

No surfactants were used in either cationic latex preparation.

EXAMPLE 6 Preparation of an Anionic Polycarbonate Latex

Two grams of polycarbonate from Example 3 were dissolved in 20 ml of THFand 30 ml of acetone. The solution was quickly added to 50 ml of waterwith good stirring. After removing the solvents and part of the water, alatex of 13.7% total solid resulted.

The polycarbonate from Example 4 was converted to an anionic latex bysimilar procedures. Total solids were found to be 11%. Both latexes hadaverage particle size diameters of about 0.1 μm.

EXAMPLE 7 Preparation of a UV dye Loaded Polycarbonate Latex

This example illustrates the use of a polycarbonate to load a UVabsorbing dye for photographic application.

Thus, 1 g of UV absorbing dye ##STR18## and 5 g of the polycarbonatefrom Example 3 were dissolved in 50 ml of THF and 50 ml of acetone. Thesolution was quickly added to 100 ml of water with moderate stirring.After the solvents were removed, a polycarbonate latex loaded with a UVabsorbing dye, with total solids of 7.2% was obtained.

The invention has been described in detail with particular reference topreferred embodiments thereof, but it will be understood that variationsand modifications can be effected within the spirit and scope of theinvention.

I claim:
 1. A photographic element comprising a layer of a polycarbonatehaving from about 0.1 to 30 mole percent of recurring units having atertiary amine acid addition salt component.